pub enum Change {
    Update {
        log: LogChange,
        expected: PreviousValue,
        new: Target,
    },
    Delete {
        expected: PreviousValue,
        log: RefLog,
    },
}
Expand description

A description of an edit to perform.

Variants

Update

Fields

log: LogChange

The desired change to the reference log.

expected: PreviousValue

The expected value already present in the reference. If a ref was existing previously it will be overwritten at MustExistAndMatch(actual_value) for use after the transaction was committed successfully.

new: Target

The new state of the reference, either for updating an existing one or creating a new one.

If previous is not None, the ref must exist and its oid must agree with the previous, and we function like update. Otherwise it functions as create-or-update.

Delete

Fields

expected: PreviousValue

The expected value of the reference, with the MustNotExist variant being invalid.

If a previous ref existed, this value will be filled in automatically as MustExistAndMatch(actual_value) and can be accessed if the transaction was committed successfully.

log: RefLog

How to treat the reference log during deletion.

Delete a reference and optionally check if previous is its content.

Implementations

Return references to values that are the new value after the change is applied, if this is an update.

Return references to values that are in common between all variants and denote the previous observed value.

Trait Implementations

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.